Abstract:
Between 1995 and 2008, the Aquatic Mercury Cycling in the Everglades (ACME) project examined in detail the biogeochemical parameters that influence methylmercury (MeHg) production in the Florida Everglades. The interdisciplinary ACME team studied Hg cycling in the Everglades through a process-based, biogeochemical lens (Hurley et al. 1998). In the Everglades, as in most other ecosystems, inorganic ... mercury is transformed into methylmercury primarily by the action of anaerobic bacteria in surficial sediments and soils. The ACME project has been a collaborative research effort designed to understand the biogeochemical drivers of mercury cycling in the Greater Florida Everglades. The project is led be a team of scientists from the USGS and the Smithsonian Institution, with additional collaborators from the University of Wisconsin, Texas A&M, the SFWMD and FL DEP. ACME’s main objective has been to define the key processes that control the fate and transport of Hg in the Everglades. The study has used a process-oriented, multi-disciplinary approach, focusing on a suite of intensively-studied sites across the trophic gradient of the Water Conservation Areas and Everglades National Park. Since 1995, a core set of sites has been examined in detail through time, including changes in season and in hydrology. The biogeochemical parameters examined focus on those that impact net methylmercury (MeHg) production, and include sulfur, carbon and nutrient biogeochemistry. The study examined Hg and MeHg concentrations, and associated biogeochemical parameters in surface waters, soils, periphyton, emergent plants and biota. The core study sites have been supplemented with survey data across many additional sites in the Greater Everglades Ecosystem. The field study was also supplemented with experimental studies of Hg complexation, photochemistry, and bioavailability. The ACME project has been funded by a variety of agencies including the USGS, NSF, EPA, SFWMD and FL DEP.

Purpose:
In the mid-1990’s, the State of Florida began to recognize elevated MeHg accumulation in Everglades fish. Concentrations of MeHg in fish posed health risks to people utilizing that resource, and bioaccumulation of MeHg posed risks to fish, wading birds, and mammals in the ecosystem. ACME was designed to evaluate the processes that led to excessive net MeHg production and bioaccumulation in parts of the Everglades.

LOGICAL CONSISTENCY REPORT: Data collected include water, pore water and soil chemistry data, plus some microbial rate measurements, for multiple sites in the Greater Everglades Ecosystem. Site types focused on marsh sites in sloughs, but also included canals, mangrove systems, rivers and Lake Okeechobee. The full parameter list is ... given in the parameter table. The site list is given in the sites table. Not all sites have data for all parameters. On any given sampling, samples were generally collected at one time during daylight hours, although replicate samples were often collected.

COMPLETENESS REPORT: Data were collected from more than 300 sites on more than 100 dates over the course of the study. Not all sites were sampled on all dates, nor were data collected for all parameters at all sites. Sampling sites and dates varied over the course of the study. A core set of 10 intensively studied sites (WCA1LOX, ENR103, WCA2AF1, WCA2AU3, WCA2BS, WCA3A33, WCA3A15, WCA3ATH, ENPTS7 and ENPTS9) have the highest data density and the most complete set of parameters. These sites were sampled from one to 6 times per year over the course of the study.

HORIZONTAL POSITIONAL ACCURACY REPORT: Horizontal positions were established with the use of GPS equipment, often from multiple measurements and/or GPS units, and checked against GoogleEarth.

Access Constraints
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Use Constraints
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